f20 - fixing build tags

BUG=None
TEST=util.sh and verifying the tag and gcr upload

Change-Id: Iccc37abb5d7725cc4c2cd79159b11fd367eb982e
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/dev-util/+/3124104
Reviewed-by: Otabek Kasimov <otabek@google.com>
Reviewed-by: Sean McAllister <smcallis@google.com>
Tested-by: Sean McAllister <smcallis@google.com>
Commit-Queue: Sean McAllister <smcallis@google.com>
diff --git a/test/docker/util.sh b/test/docker/util.sh
index c3c58f1..b8fc34a 100644
--- a/test/docker/util.sh
+++ b/test/docker/util.sh
@@ -58,7 +58,7 @@
   # @FUNCTION: build_image
   # @USAGE: Docker builds + uploads to the registry.
   # @DESCRIPTION:
-  sudo docker build -f "${docker_file}" -t "${image_path}" "${build_context}"
+  sudo docker build -f "${docker_file}" -t "${image_path}:${build_version}" "${build_context}"
   sudo docker login -u oauth2accesstoken -p "$(gcloud auth print-access-token)" "https://${registry_name}"
   sudo docker push "${image_path}":"${build_version}"
 }